Files
tasks/common/persistence/sql/sqlplugin/postgresql/queue.go
T
Tim Deeb-SwihartandGitHub be7b5514a5 Reconnect to SQL databases when connections fail (#5926)
## What changed?

Both our PostgreSQL and MySQL database backends will now automatically
reconnect to the database when certain errors occur: all errors chosen
have been experienced when testing this behavior through an AWS Aurora
RDS failover of either MySQL or PostgreSQL.

For both backends we will reconnect when we see:
- `ECONNRESET`
- `ECONNABORTED`
- `ECONNREFUSED`
- `io.EOF`
- `io.ErrUnexpectedEOF`
- `database/sql/driver.ErrBadConn`

for postgres we will also reconnect on the following SQLStates:
- `25006` read-only transaction
- `57P03` cannot connect now
- `0A000` feature not supported, but ONLY when the message is `cannot
set transaction read-write mode during recovery`

for mysql we will also reconnect when we see the following error codes:
- `1040` too many connections 
- `1792` read-only transaction (SQLstate `25006`)
- `1836` running in read-only mode

This logic is easily extensible should we discover more failure modes
over time

## Why?

We've had multiple community reports of Temporal problems during RDS
failover. One part of this is the fact that we wouldn't necessarily
reconnect; we were at the whims of our chosen SQL abstraction's
connection pooling logic.

## How did you test it?

I manually tested this functionality in the presence of repeated RDS
failovers: 

- [x] postgres12 plugin with pq driver
- [x] postgres12 plugin with pgx driver
- [x] mysql plugin

Automated testing will be added to our regular testing pipelines once
our infrastructure friends have added the support I need (it's in
progress)

## Potential risks

We're concerned there's a correctness issue in our PostgreSQL backend
that's related to our behavior during an RDS failover. If we merge this
before I figure out what's going on, we could hide the issue and make it
harder to reproduce.

## Documentation
N/A

## Is hotfix candidate?
Yes?
2024-05-17 16:59:15 -07:00

181 lines
5.7 KiB
Go

// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc. All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package postgresql
import (
"context"
"database/sql"
"go.temporal.io/server/common/persistence"
"go.temporal.io/server/common/persistence/sql/sqlplugin"
)
const (
templateEnqueueMessageQuery = `INSERT INTO queue (queue_type, message_id, message_payload, message_encoding) VALUES(:queue_type, :message_id, :message_payload, :message_encoding)`
templateGetMessageQuery = `SELECT message_id, message_payload, message_encoding FROM queue WHERE queue_type = $1 and message_id = $2`
templateGetMessagesQuery = `SELECT message_id, message_payload, message_encoding FROM queue WHERE queue_type = $1 and message_id > $2 and message_id <= $3 ORDER BY message_id ASC LIMIT $4`
templateDeleteMessageQuery = `DELETE FROM queue WHERE queue_type = $1 and message_id = $2`
templateRangeDeleteMessagesQuery = `DELETE FROM queue WHERE queue_type = $1 and message_id > $2 and message_id <= $3`
templateGetLastMessageIDQuery = `SELECT message_id FROM queue WHERE message_id >= (SELECT message_id FROM queue WHERE queue_type=$1 ORDER BY message_id DESC LIMIT 1) FOR UPDATE`
templateCreateQueueMetadataQuery = `INSERT INTO queue_metadata (queue_type, data, data_encoding, version) VALUES(:queue_type, :data, :data_encoding, :version)`
templateUpdateQueueMetadataQuery = `UPDATE queue_metadata SET data = :data, data_encoding = :data_encoding, version = :version+1 WHERE queue_type = :queue_type and version = :version`
templateGetQueueMetadataQuery = `SELECT data, data_encoding, version from queue_metadata WHERE queue_type = $1`
templateLockQueueMetadataQuery = templateGetQueueMetadataQuery + " FOR UPDATE"
)
// InsertIntoMessages inserts a new row into queue table
func (pdb *db) InsertIntoMessages(
ctx context.Context,
row []sqlplugin.QueueMessageRow,
) (sql.Result, error) {
return pdb.NamedExecContext(ctx,
templateEnqueueMessageQuery,
row,
)
}
func (pdb *db) SelectFromMessages(
ctx context.Context,
filter sqlplugin.QueueMessagesFilter,
) ([]sqlplugin.QueueMessageRow, error) {
var rows []sqlplugin.QueueMessageRow
err := pdb.SelectContext(ctx,
&rows,
templateGetMessageQuery,
filter.QueueType,
filter.MessageID,
)
return rows, err
}
func (pdb *db) RangeSelectFromMessages(
ctx context.Context,
filter sqlplugin.QueueMessagesRangeFilter,
) ([]sqlplugin.QueueMessageRow, error) {
var rows []sqlplugin.QueueMessageRow
err := pdb.SelectContext(ctx,
&rows,
templateGetMessagesQuery,
filter.QueueType,
filter.MinMessageID,
filter.MaxMessageID,
filter.PageSize,
)
return rows, err
}
// DeleteFromMessages deletes message with a messageID from the queue
func (pdb *db) DeleteFromMessages(
ctx context.Context,
filter sqlplugin.QueueMessagesFilter,
) (sql.Result, error) {
return pdb.ExecContext(ctx,
templateDeleteMessageQuery,
filter.QueueType,
filter.MessageID,
)
}
// RangeDeleteFromMessages deletes messages before messageID from the queue
func (pdb *db) RangeDeleteFromMessages(
ctx context.Context,
filter sqlplugin.QueueMessagesRangeFilter,
) (sql.Result, error) {
return pdb.ExecContext(ctx,
templateRangeDeleteMessagesQuery,
filter.QueueType,
filter.MinMessageID,
filter.MaxMessageID,
)
}
// GetLastEnqueuedMessageIDForUpdate returns the last enqueued message ID
func (pdb *db) GetLastEnqueuedMessageIDForUpdate(
ctx context.Context,
queueType persistence.QueueType,
) (int64, error) {
var lastMessageID int64
err := pdb.GetContext(ctx,
&lastMessageID,
templateGetLastMessageIDQuery,
queueType,
)
return lastMessageID, err
}
func (pdb *db) InsertIntoQueueMetadata(
ctx context.Context,
row *sqlplugin.QueueMetadataRow,
) (sql.Result, error) {
return pdb.NamedExecContext(ctx,
templateCreateQueueMetadataQuery,
row,
)
}
func (pdb *db) UpdateQueueMetadata(
ctx context.Context,
row *sqlplugin.QueueMetadataRow,
) (sql.Result, error) {
return pdb.NamedExecContext(ctx,
templateUpdateQueueMetadataQuery,
row,
)
}
func (pdb *db) SelectFromQueueMetadata(
ctx context.Context,
filter sqlplugin.QueueMetadataFilter,
) (*sqlplugin.QueueMetadataRow, error) {
var row sqlplugin.QueueMetadataRow
err := pdb.GetContext(ctx,
&row,
templateGetQueueMetadataQuery,
filter.QueueType,
)
if err != nil {
return nil, err
}
return &row, err
}
func (pdb *db) LockQueueMetadata(
ctx context.Context,
filter sqlplugin.QueueMetadataFilter,
) (*sqlplugin.QueueMetadataRow, error) {
var row sqlplugin.QueueMetadataRow
err := pdb.GetContext(ctx,
&row,
templateLockQueueMetadataQuery,
filter.QueueType,
)
if err != nil {
return nil, err
}
return &row, err
}